Intelligent automated assistants (or digital assistants) can provide a beneficial interface between human users and electronic devices. Such assistants can allow users to interact with devices or systems using natural language in spoken and/or text forms. For example, a user can provide natural language input representing a user request to a digital assistant operating on an electronic device. The digital assistant can interpret the user's intent from the input and operationalize the user's intent into tasks. The tasks can then be performed by executing one or more services of the electronic device, and a relevant output responsive to the user request can be returned to the user.
Digital assistants can interpret natural language input by parsing the natural language input to obtain one or more natural language parsing results. The one or more parsing results can identify relevant semantic information in the natural language input and can be used to generate one or more tasks corresponding to the natural language input. In some instances, the one or more generated tasks, when performed by the digital assistant, may fail to accomplish the user request represented by the natural language input. This may be because the one or more parsing results contain insufficient and/or erroneous semantic information about the natural language input. Accordingly, improved natural language processing techniques are desirable.